| <!DOCTYPE html> | |
| <div>The blue square should be at the top-left corner of the iframe.</div> | |
| <iframe srcdoc=" | |
| <!DOCTYPE html> | |
| <body style='writing-mode: vertical-rl; overflow: scroll; margin: 0'> | |
| <div style='position: absolute; top: 0; left: 0; width: 100px; height: 100px; background: blue'></div> | |
| </body>"> | |
| </iframe> |